Blade contact for electric plugs

ABSTRACT

In a blade contact for electric plug connectors with a strip-like contact part, a supporting body securable on the plug casing, and with crimping attachments for securing an electrical conductor and its insulation jacket on the blade contact, the support is made safer while reducing the constructional expenditure, and the flow of current is enhanced by the arrangement of a sheet-metal blank cut to size with a substantially rectangular section extending across partial lengths of said blank for forming the contact part, and with a tab on each side projecting beyond the section of forming the contact part, as well as with tabs disposed in line with the section and projecting laterally beyond the latter for forming crimping attachments, and of which the tabs are bent back outward rearwardly, whereas the tabs for the crimping attachments are set obliquely outward.

FIELD OF THE INVENTION

The invention relates to a blade contact for electric plug connectorswith a strip-like contact part, a supporting body fixable on the plugcasing, and with crimping attachments for securing an electricalconductor and its insulating jacket on the blade contact.

BACKGROUND OF THE INVENTION

It is known that blade contacts have to be fixed in the plug casing inthe direction of plugging. For this purpose, one known blade contact hasa contact part provided with a fastening recess and having transverselyprojecting jags, which are folded back across partial lengths, restingone on top of the other. Due to the fastening recess, the blade contactis mechanically unstable and weakened in the cross section next to therecesses; this unfavorably influences the flow of current. Furthermore,the blade contact is not capable of miniaturization. Another known bladecontact is embraced across a partial length by a box tube-like, moldedsheet-metal part for creating a supporting body, which part can beslipped on and secured on the contact part by means of tongue-shapedjags that can be bent into recesses of the contact part. The moldedsheet-metal part acting as the supporting body is not only costly toproduce, but also does not safely secure the contact blade.

SUMMARY OF THE INVENTION

The object of the invention is to reduce the constructional expenditurefor blade contacts of the above type, to make the support of the bladecontact in the plug casing more secure, and to create the preconditionfor a favorable flow of current.

According to the invention, this object is achieved as follows. A metalsheet is cut to size, with a substantially rectangular section extendingacross partial lengths thereof to form the contact part, and a tab oneach of its two sides projecting beyond the rectangular section to formthe supporting body, as well as additional tabs disposed in line withthe section and laterally projecting beyond the latter for formingcrimping attachments. The metal sheet is folded in by 90° on itself in aplane-parallel way along a common fold line substantially over the axiallength of the section forming the contact part and of the tabs, and thetabs of which are bent back outwardly, whereas the tabs for the crimpingattachments are set obliquely outwards, or with a spacing parallel withthe plane of the fold line. The blade contact can be formed from asingle sheet-metal blank cut to size, by simple bending processes. Thisresults in a simple development and advantageous realizability of theblade contact in terms of tool engineering, and assures exact securingof its position in the plug casing. Furthermore, the blade contact ischaracterized by a mechanical ruggedness that permits the utilization ofmaterials having lower strength, but high electrical conductivity.Finally, by omitting fastening recesses, the flow of current in theblade contact is left unimpaired.

Preferably, the tabs have curved segments and plane segments connectingup with said curved segments, whereby the curved segments and the planesegments of the tabs project beyond the section of the sheet-metal blankcut to size forming the contact part. In this connection, the curvedsegments are shaped in such a way that the section forming the contactpart and the tabs forming the supporting body have a substantiallymeander-like cross section transversely to the direction of plugging. Itis possible in this connection to design the supporting body with anydesired width relative to the contact part by selecting the radii on thecurved segments accordingly.

In developing the blade contact, provision is made that the planesegments of the tabs extend either in a plane-parallel way relative toeach other, or obliquely outwards toward the free end. In thisconnection, the tabs can be wholly or partly rigid or elastic, so thatthe blade contact with the tabs is insertable and securable in the plugcasing under prestress, if need be.

Furthermore, provision is made to bend the free end of the plane segmentof at least one tab inwardly across a partial length and/or partialwidth transversely to the plane of the fold line in order to form a boxtube-like supporting body. Preferably, the free ends of both segmentshave inward bends directly against each other approximately across halfof their axial length.

In a further development, the curved segments have at least one inwardor outward depression serving as a reinforcement, for example acorrugation. In this way, unintentional bending back of the tabs isavoided, for example when the blade contact is being inserted in theplug casing. Furthermore, the tabs may have recesses in the zone of thecurved segments and/or across partial widths of the plane segments.

Finally, measures for easier plugging of the blade contact in associatedcontact sockets are achievable if the section forming the contact parthas a slotting extending at the free plug end in the fold line across apartial length, and if the ends of the contact part segments so formednext to the slotting are bent inwardly toward the free end. In addition,offsets, for which provision may be made, if need be, in the marginaledge zones of the longitudinal edges of the contact part segments,permit the formation of an insertion tip on the blade contact.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained on the basis of an exemplaryembodiment shown in the drawing, in which:

FIG. 1 shows a sectional view of a plug casing with a blade contact;

FIG. 2 is a perspective view of a blade contact;

FIG. 3 is a lateral view of a blade contact;

FIG. 4 is a top plan view of a blade contact;

FIG. 5 shows a part section of a blade contact within the zone of lineV--V of FIG. 2;

FIGS. 6 and 7 show part sections of a blade contact within the zone ofthe supporting bodies in accordance with suitably modified embodiments;

FIG. 8 is a top plan view of a sheet-metal blank cut to size for a bladecontact; and

FIG. 9 shows an enlarged view of a blade contact within the zone of theplug end, in a lateral view.

DETAILED DESCRIPTION

The drawings show a plug casing 1 for receiving the blade contacts 2.The individual blade contact 2 has a contact part 3, a supporting body 4for the purpose of axial fixation of the blade contact 2 in the plugcasing 1, and the crimping attachments 5 and 6. The blade contact 2 isformed by one single cut-to-size sheet-metal blank 7 which, acrosspartial lengths, has a substantially rectangular section 8 for formingthe contact part 3, and the tabs 9, 10 and 11 for forming the supportingbody 4 and the crimping attachments 5 and 6, the tabs laterallyprojecting beyond the section 8. With the section 8, the cut-to-sizesheet-metal blank 7 is folded along a fold line 12 across the length ofthe blade contact 2 and the supporting body 4 by 90° onto the tabs 9extending on both sides of the fold line 12. FIG. 2 shows that the tabs9 forming the supporting body 4 are bent back across the curved segments9', resulting within the zone of the supporting body 4 in asubstantially-meander-shaped cross section through the contact part 3and the tabs 9 (FIG. 5). The curved segments 9' and the plane segments9" connecting up with the curved segments 9' project beyond the contactpart 3 parallel with the plane of the fold line, forming in this waysupporting surfaces on the supporting body which, when the blade contact2 is inserted in the plug casing 1, come to rest against the plug casingsurfaces at 13 (FIG. 1). In the plug casing 1, the supporting body 4 isgrippable from behind by a bendable attachment 14 flexibility mounted onthe plug casing (FIG. 1). The attachments is fixable in the grippingposition by means of a clamping body 16, which can be pushed into theplug casing 1. The curved segments 9', or the curved segments 9' andparts of the plane segments 9," can be provided with one or moredepressions 15 (FIG. 5), which serve to rigidify the curved segments 9'and help to prevent unintentional bending back of the tabs 9.

In the embodiment of FIG. 6, the curved segments 9' and the planesegments 9" of the tabs 9 are provided with recesses 18, whichpreferably are trapezoidal. By having clamping bodies (not shown)mounted rigidly on the plug casing engage in the recesses 18, it ispossible to obtain or support an axial fixation of the blade contact.

In the embodiment of FIG. 7, the free ends of the plane segments 9' arebent inwardly across part of their length 9'" in the direction of thefold line plane 12, forming in this way a box tube-like supporting body4 of great stability.

The tabs 10 and 11 of the cut-to-size sheet-metal blank 7 are obliquerelative to the plane of the fold line of the contact part 3 and servefor securing an electrical conductor (not shown) or its insulation.

FIGS. 8 and 9 show that the contact part 3 is provided with a slot 20 atthe free end of the section 8 across a partial length, and that the freesection ends 8', 8" so formed are bent inwardly against each other toform an insertion slope. The ends 8', 8" facilitate the insertion of theblade contact 2 in associated contact sockets (not shown). In addition,the marginal edges of the free ends 8', 8" are provided with offsets 23,which permit the formation of an insertion tip.

We claim:
 1. Blade contact for electric plug connectors, said bladecontact comprising:(a) a strip-shaped contact part (3) formed from aplane metal sheet (7) having a substantially rectangular section (8)across portions of a length of said sheet, said contact part (3)comprising a folded segment forming a supporting body (4) to be heldbetween latching surfaces within a plug housing so as to fix saidcontact in said plug housing; (b) two tabs (9) respectively projectingfrom each of two sides of said segment, said tabs being bent outwardlyto form said supporting body (4); (c) additional tabs (10, 11) arrangedon said sheet forming crimp attachments (5, 6) for fixing an electricalconductor and insulating jacket of said conductor; (d) said rectangularsection forming said contact part (3) and each said two tabs (9) beingfolded downwardly by 90° across a substantially axial partial lengthalong a fold line (12) disposed along an axis of said sheet (7), so thatportions of said two tabs extend alongside each side of the foldedcontact part.
 2. Blade contact according to claim 1, wherein said twotabs (9) comprise curved segments (9') and plane segments (9")connecting up to said curved segments.
 3. Blade contact according toclaim 2, wherein said curved segments (9') and said plane segments (9")project beyond said rectangular section forming said contact part (3).4. Blade contact according to claim 1, wherein, within the zone of saidtwo tabs (9), said rectangular section and said two tabs jointly form asubstantially meander-shaped cross-section transversely to a directionof plugging.
 5. Blade contact according to claim 1, wherein said planesegments (9") of said two tabs (9) are located in mutually parallelplanes.
 6. Blade contact according to claim 1, wherein said two tabs (9)are resiliently deflectable.
 7. Blade contact according to claim 1,wherein a free end of said plane segment (9") of at least one of saidtwo tabs (9) is bent inwardly transversely to the plane of said foldline (12) across a partial length and partial width so as to form a boxtube-like supporting body.
 8. Blade contact according to claim 5,wherein said curved segments (9') have at least one inward depression(15) serving as a stiffening means.
 9. Blade contact according to claim7, wherein said curved segments (9') have at least one outwarddepression (15) serving as a stiffening means.
 10. Blade contactaccording to claim 1, wherein said two tabs (9) have recesses (18)within the zone of said curved segments (9') and partial widths of saidplane segments (9").
 11. Blade contact according to claim 1, wherein thesection (8) forming said contact part (3) has a slot (20) at a free plugend in said fold line (12) across a partial length, and ends of thecontact part sections (8, 8') extending next to said slot (20) are bentinwardly toward said free end.
 12. Blade contact according to claim 11,wherein said contact part sections (8, 8') have offsets (23) in marginalzones of longitudinal edges of said rectangular section (8).